WO2025237807A1

WO2025237807A1 - A method for operating a wireless network with hybrid links

Info

Publication number: WO2025237807A1
Application number: PCT/EP2025/062631
Authority: WO
Inventors: Octavio Alejandro SANTANA ARNAIZ; Anteneh Alemu ABBO; John Brean Mills
Original assignee: Signify Holding BV
Current assignee: Signify Holding BV
Priority date: 2024-05-17
Filing date: 2025-05-08
Publication date: 2025-11-20
Anticipated expiration: 2026-11-17

Abstract

A method (800) for operating a wireless network (100) comprising a system controller (110) and a plurality of nodes (301-30n), the method (800) comprising steps of: operating (S801) the wireless network (100) in a network control mode according to a first communication protocol; operating (S802) the wireless network (100) in a data streaming mode according to a second communication protocol; wherein the first communication protocol supports bi-directional communication over multi-hop routing among the system controller (110) and the plurality of nodes (301-30n), and the second communication protocol supports broadcasting from the system controller (110) to one or more nodes (301-30n) out of the plurality of nodes (301-30n) based on adaptive frequency hopping.

Description

A method for operating a wireless network with hybrid links

FIELD OF THE INVENTION

The invention relates to the field of wireless communication. More particularly, various methods, apparatus, and systems are disclosed herein related to operating a wireless network with hybrid links.

BACKGROUND OF THE INVENTION

ZigBee, Thread and Bluetooth Mesh are examples of wireless network that are targeted at loT applications such as lighting and building automation. They provide a low latency, low-rate service that enables messages to be passed between, for example, a light switch and one or more luminaires. To enable messages to be routed correctly, each node on the wireless network is assigned a local network unicast address and may be addressed either directly as an individual node or, via a group address, as a member of a group. Once configured, such networks are typically expected to operate autonomously.

On the other hand, as a replacement to cable based lighting control, wireless DMX (Digital Multiplex) solutions combine lighting network control/configuration and streaming in a single wireless radio protocol, which are typically offered by small companies operating in a niche entertainment market. Consequently, wireless DMX solutions are relatively more expensive than general-purpose Wi-Fi/ZigBee/BLE solutions.

In addition, for countries within the European Union and/or countries subject to the radio regulations set by the European Conference of Postal and Telecommunications Administrations (CEPT), there are different transmitter power limits for frequency hopping spread spectrum and non-frequency hopping devices. For the 2400 - 2483.5 MHz license exempt band this results in adaptive frequency hopping spread spectrum devices (AFHSS) being able to use up to +20dBm equivalent isotropic radiated power (e.i.r.p) while the nonfrequency hopping devices are limited to a maximum of +20dBm e.i.r.p with the additional restraint of a maximum power spectral density of lOdBm/MHz. In the case of IEEE 802.15.4-2006 based radios such as Zigbee, this results in a maximum transmitted power level of +13dBm e.i.r.p which has a range limiting effect. Benefiting from the mesh networking approach of Zigbee, range extension is possible. However, there is a latency penalty, which makes Zigbee unsuitable for highly dynamic, real-time lighting control data protocols such as DMX-512A as used in entertainment lighting.

US2008170601A1 relates to a radio transceiver system that comprises a control system, a first radio transceiver for transmitting control data formatted in at least an industry-standard control protocol from the control system to at least a second radio transceiver, a second radio transceiver for receiving control data from the first radio transceiver and communicating the same to at least a load, wherein the control data is transmitted from the first radio transceiver to the second radio transceiver utilizing an frequency hopping spread spectrum broadcast.

NARAYAN K SHIV ET AL, “Design and implementation of polyphase based FHSS modulator using GNU radio and SDR” relates to design and implementation of polyphase based FHSS modulator.

SUMMARY OF THE INVENTION

It is preferable to run system configuration and bidirectional communication RDM monitoring on a more secured network with reliable whole network coverage, and in the meanwhile these tasks are less frequent, less bandwidth intensive and typically less latency critical. Thus, wireless mesh network is a good candidate to implement such tasks.

On the other hand, it is a highly latency sensitive application to stream DMX data. It is thus considered to be beneficial to use an adaptive frequency hopping spread spectrum radio in broadcast mode. This provides both robustness against interference and permits use of the maximum transmitter power levels under EU/CEPT regulations in order to cover long ranges in a single radio transmission (no mesh networking or message relaying needed) to satisfy the low latency requirement.

Therefore, to address the application needs of entertainment lighting, it is recognized by the inventor that it is beneficial to realize DMX-512A/Remote Device Management (RDM) communication by using hybrid links, such as communication links based on frequency hopping spread spectrum and direct sequence spread spectrum respectively. Considering that nowadays dual-mode radios capable to support both communication links are widely deployed in many lamps and luminaires, the solution disclosed in the present invention takes advantage of the features of each individual mode of the standard dual-mode radio to serve the targeted application. More particularly, the goal of this invention is achieved by a method as claimed in claim 1, by a node as claimed in claim 8, and by a wireless network as claimed in claim 11.

In accordance with a first aspect of the invention a method is provided. A method for operating a wireless network comprising a system controller and a plurality of nodes, the method comprising steps of: operating the wireless network in a network control mode according to a first communication protocol; operating the wireless network in a data streaming mode according to a second communication protocol; wherein the first communication protocol supports bi-directional communication over multihop routing among the system controller and the plurality of nodes, and the second communication protocol supports broadcasting from the system controller to one or more nodes out of the plurality of nodes based on adaptive frequency hopping.

The wireless network may operate in at least two modes, the network control mode and the data streaming mode. In the network control mode, the system controller is responsible for configuring, managing or controlling one or more nodes out of the plurality of nodes in the network. In the data streaming mode, the system controller is responsible to provide continuous transmission of data packets over the network in a broadcasting manner.

The first communication protocol supports multi-hop routing, which may be a wireless mesh communication protocol, such as Zigbee mesh, BLE mesh, Thread, Z-Wave, or another short range wireless mesh communication protocol.

The second communication protocol supports at least broadcasting from the system controller to one or more nodes based on frequency hopping. It may also support unicast or multicast. The use of frequency hopping for broadcasting has the benefits on improved robustness against interference and a higher transmitter power level to over longer transmission distance.

Advantageously, the method further comprises a step of: broadcasting data according to a Digital Multiplex (DMX) protocol from the system controller to the one or more nodes in the data streaming mode.

The Digital Multiplex (DMX) protocol is a communication protocol used in the entertainment industry to control stage lighting and effects. It was first introduced in 1986 by USITT (United States Institute for Theatre Technology) as a standardized protocol for lighting control systems. DMX is a serial communication protocol that uses a single twisted pair of wires to transmit data between lighting fixtures and a DMX controller. It allows for up to 512 channels of control, each of which can be assigned a value between 0 and 255. These values are used to control various lighting attributes, such as intensity, colour, and movement. DMX has become the standard protocol for controlling lighting in the entertainment industry, and is used in a variety of applications, including concerts, theatre productions, and architectural lighting.

The wireless version of the DMX protocol is also called Wireless DMX or W- DMX. This protocol allows for wireless transmission of DMX data between lighting fixtures and controllers, eliminating the need for physical cables. Wireless DMX uses radio frequency (RF) technology to transmit DMX data between fixtures and controllers. It typically operates in the 2.4 GHz frequency band, which is a license-free frequency range used by many wireless devices. Wireless DMX is particularly useful in situations where running physical cables is difficult or impractical, such as outdoor events or large venues with complex lighting setups.

Beneficially, the method further comprises a step of: transmitting a configuration or control signal from the system controller to the plurality of nodes in the network control mode.

By transmitting a configuration or control signal from the system controller to the plurality of nodes according to the first communication protocol with multi-hop routing capability, it is beneficial to guarantee that the configuration or control signal can be delivered to all the destined nodes in the network.

In one example, the configuration or control signal is according to a Remote Device Management, RDM, protocol.

Remote Device Management (RDM) is a protocol that was developed to enhance the functionality of DMX-based lighting control systems. RDM allows for two-way communication between controllers and lighting fixtures or dimmers, enabling remote monitoring and management of lighting devices. RDM works by adding a bi-directional communication channel to the DMX protocol. This allows DMX devices, such as lighting devices, to respond to messages sent by the controller, providing information about their status, configuration, and other parameters. RDM messages can also be used to remotely configure and control DMX devices, allowing for more efficient setup and troubleshooting. RDM is now widely adopted in the entertainment industry and is supported by many lighting fixture manufacturers.

Preferably, the method further comprises the steps of: initializing the wireless network in the network control mode; switching the wireless network between the data streaming mode and the network control mode according to a time schedule.

By switching between the two modes of operation of the network according to a time schedule, the network can be controlled in a coordinated manner. This may be especially beneficial in the case that both modes of operation of the network is supported by a single dual-mode radio of the system controller and/or one or more nodes out of the plurality of nodes.

Advantageously, the time schedule may be predetermined or configurable according to at least one of a real-time traffic load for data streaming, a latency requirement of data streaming, a latency requirement of the configuration or control signal, a user input, a trigger event, or a combination thereof.

In one option, the time schedule may be predetermined or preconfigured, and follows a fixed pattern. In another option, the time schedule is configurable or determined adaptively, which brings enhanced flexibility and efficiency of the system.

In one example, the second communication protocol supports broadcasting based on adaptive frequency hopping.

Adaptive frequency hopping is used in wireless communication systems to improve the reliability and security of data transmission, which can dynamically change the frequency used for transmission based on the wireless channel conditions. In adaptive frequency hopping, the system controller continuously monitors the channel and switches to a different channel if it detects any interference or congestion. This helps to reduce the likelihood of data loss or corruption due to interference from other devices, systems, or environmental factors.

Additionally, adaptive frequency hopping can improve the security of communication by making it more difficult for unauthorized users to intercept or jam the transmission. With dynamical channel switching, the system makes it more difficult for an attacker to predict the channel switching pattern and intercept the data.

In another example, the second communication protocol supports broadcasting based on simultaneous multicarrier frequency hopping or adaptive simultaneous multicarrier frequency hopping.

Simultaneous Multicarrier Frequency Hopping (SMFH) is a wireless communication technique that involves the use of multiple carrier frequencies that are hopped between simultaneously. The idea behind SMFH is to increase the robustness of wireless communication systems by spreading the signal over multiple frequency channels, which makes it more resistant to interference and fading. In SMFH, each carrier frequency is typically hopped independently and randomly, which makes it more difficult for an eavesdropper to intercept the signal. SMFH is commonly used in military, satellite, and wireless communication systems, where a high level of security and reliability is required.

Adaptive Simultaneous Multicarrier Frequency Hopping (ASMFH) is an advanced version of Simultaneous Multicarrier Frequency Hopping (SMFH) that uses adaptive algorithms to dynamically adjust the hopping patterns based on the current channel conditions. In ASMFH, the hopping pattern is adjusted in real-time to optimize the system performance and minimize the effects of interference, fading, and other sources of noise.

An ASMFH algorithm may analyse the channel quality and adjust the hopping pattern to avoid frequency channels with high interference or fading, and to exploit channels with low interference and high signal-to-noise ratio (SNR). This makes ASMFH more effective than SMFH in challenging environments, where the radio frequency (RF) spectrum is crowded and noisy, such as the free licensed ISM (Industrial, Scientific, and Medical) band.

In accordance with a second aspect of the invention a node is provided. A node out of a plurality of nodes comprised in a wireless network; wherein the wireless network comprises a system controller and the plurality of nodes; the node comprising: a transceiver configured to operate according to a first communication protocol; a first receiver configured to operate according to a second communication protocol; and a controller configured to: o enable the transceiver when the wireless network is in a network control mode; and o enable the first receiver when the wireless network is in a data streaming mode; wherein the first communication protocol supports bi-directional communication over multihop routing among the system controller and the plurality of nodes, and the second communication protocol supports broadcasting from the system controller to one or more nodes out of the plurality of nodes based on frequency hopping.

In one example, the first receiver is a polyphase channelizer receiver. A polyphase channelizer receiver is a type of digital signal processing system that is used to separate a wideband signal into multiple narrowband channels. It works by using a bank of digital filters that are designed to extract specific frequency channels from the input signal. The output of each filter represents a different frequency channel, and the combination of all the outputs is used to reconstruct the original signal. Polyphase channelizer receivers are commonly used in radio communication systems and radar systems to process signals that are spread over a wide frequency range.

Therefore, the polyphase channelizer receiver enables simultaneous reception and synchronisation of all available hopping channels at once. This means that true adaptive Frequency Hopping Spread Spectrum (FHSS) (or even simultaneous multicarrier frequency hopping and adaptive simultaneous multicarrier frequency hopping) can now be practically implemented without penalties - there is no need to tune an RF local oscillator from one hopping frequency to another which takes time and limits reception to only a single channel at a time unless multiple independent receivers are implemented in the receiver.

This option has a further advantage that a diversity scheme can be implemented whereby data for transmission can be sent simultaneously on multiple noiseless hopping frequencies at once to increase the robustness. It also means that an intelligent decision can be made on the spot regarding which channel or channels are of sufficient quality (good SNR) at a particular moment in time for data transmission. As all channels are received simultaneously, there is no need to waste channels on providing information over the hopping sequence so more channels may be available for data transmission.

In another example, the first receiver is comprised in the transceiver, and the controller is further configured to switch the transceiver to operate according to the first communication protocol and the second communication protocol depending on whether the wireless network is in the network control mode or in the data streaming mode.

According to this option, the transceiver is capable to support both the first communication protocol and the second communication protocol, such as a dual-mode radio. And then the dual-mode radio can be configured to operate either according to the first communication protocol or the second communication protocol depending on the operation mode of the wireless network.

In accordance with a third aspect of the invention a wireless network is provided. A wireless network comprising a system controller and a plurality of nodes according to the present invention; wherein the system controller is configured to: transmit a configuration or control signal to one or more nodes out of the plurality of nodes in the network control mode; and broadcast data to one or more nodes out of the plurality of nodes based on frequency hopping in the data streaming mode.

A system controller is a device that manages and controls the resources and activities of a network, for example, the system controller may be responsible for managing and maintaining the network's hardware, software, and communication protocols. The system controller is typically a central point of control for the network.

Beneficially, one or more nodes out of the plurality of nodes are integrated in or attached to a luminaire.

By embedding one or more nodes of the wireless network in a lighting system, it may have the benefit of making use of the lighting infrastructure to deploy the wireless network. In the meanwhile, the control signal received by the node from a lighting controller may be used directly to control the colour, intensity, or other lighting attributes of the lighting fixture or luminaire, which makes the system also more efficient.

In this case, the system controller may be a central lighting controller of a lighting system, which is a type of lighting control system that centrally manages and controls the lighting in a building or other space. The central lighting controller is typically a hardware device that is installed in a central location, such as a control room or server room. The controller is connected to the lighting fixtures throughout the building and can be used to turn lights on and off, adjust the brightness of lights, and change the colour of lights.

Preferably, the system controller is a controller node according to a Digital Multiplex (DMX) system, a Remote Device Management, RDM, system, or another digital communication protocol for lighting control.

The system controller may also be according to a combination of two or more aforementioned digital communication protocols for lighting control.

In one example, the system controller is further configured to broadcast based on adaptive frequency hopping, simultaneous multicarrier frequency hopping, or adaptive simultaneous multicarrier frequency hopping.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference characters generally refer to the same parts throughout the different figures. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. Fig. 1 illustrates a wireless network comprising a system controller and a plurality of nodes;

Fig. 2 illustrates one example of a wireless network for lighting control;

Fig. 3 illustrates a basic block diagram of a node;

Fig. 4 exemplarily shows a flow chart of a method for operating a wireless network;

Fig. 5 exemplarily shows a flow chart of a method for operating a wireless network; and

Fig. 6 shows one example of a method for operating a wireless network.

DETAILED DESCRIPTION OF EMBODIMENTS

The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments. Upon reading the following description in light of the accompanying drawings, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

FIG. 1 illustrates a wireless network 100 comprising a system controller 110 and a plurality of nodes 301-30n. The system controller 110 is configured to: transmit a configuration or control signal to one or more nodes 301-30n out of the plurality of nodes 301-30n in the network control mode; and broadcast data to one or more nodes 301-30n out of the plurality of nodes 301- 3 On based on frequency hopping in the data streaming mode.

The system controller may be a central lighting controller of a lighting system, which is a type of lighting control system that centrally manages and controls the lighting in a building or other space. The central lighting controller is typically a hardware device that is installed in a central location, such as a control room or server room. The controller is connected to the lighting fixtures throughout the building and can be used to turn lights on and off, adjust the brightness of lights, and change the colour of lights. For example, the system controller 110 may be a controller node according to a Digital Multiplex DMX system, a Remote Device Management, RDM, system, or another digital communication protocol for lighting control. The system controller 110 may also support a combination of more than one lighting control protocols.

The system controller 110 may be further configured to broadcast based on frequency hopping, adaptive frequency hopping, simultaneous multicarrier frequency hopping, or adaptive simultaneous multicarrier frequency hopping.

As indicated by the solid lines in FIG. 1, the first communication protocol supports bi-directional multi-hop communication in the wireless network, which provides full network coverage for delivering configuration or control signals from the system controller to the plurality of nodes and for collecting status or sensing information from the plurality of node by the system controller.

As indicated by the dash lines in FIG. 1, the second communication protocol supports at least uni-directional communication from the system controller to the plurality of nodes for data streaming. According to the regulations, for the 2400 - 2483.5 MHz ISM band, frequency hopping spread spectrum devices (FHSS) or adaptive frequency hopping spread spectrum devices (AFHSS) may use up to +20dBm equivalent isotropic radiated power (e.i.r.p) while the non-frequency hopping devices are limited to a maximum of +20dBm e.i.r.p with the additional restraint of a maximum power spectral density of lOdBm/MHz. Thus, the second communication protocol may support longer transmission distance with a single hop, which is advantageous for broadcasting based applications. FHSS and AFHSS have further benefit on improved interference robustness.

Therefore, by having the wireless network in a dual mode operation, the system benefits from the advantages of both the first communication protocol and the second communication protocol.

For example, to run system configuration and bidirectional communication monitoring on a multi-hop mesh network, such as a Zigbee network, to satisfy the security and coverage requirements of this type of application. Although a multi-hop mesh network may introduce additional delay in propagating the signals, these tasks are typically less frequent, less bandwidth intensive and are not time critical.

On the other hand, to send the low latency streaming data using an adaptive frequency hopping spread spectrum radio in broadcast mode, it provides both robustness against interference and permits use of the maximum transmitter power levels under EU/CEPT regulations to cover a longer distance in a direct communication link, without introducing any additional latency.

Preferably, one or more nodes 301-30n out of the plurality of nodes 301-30n are integrated in or attached to a luminaire. Thus, one or more nodes of the wireless network is embedded or integrated in a lighting system, which provides the benefit of making use of an existing lighting infrastructure to deploy the wireless network. In the meanwhile, the control signal received by the node from a lighting controller may be used directly to control the colour, intensity, or other lighting attributes of the lighting fixture or luminaire. This can further improve the efficiency of the system.

FIG. 2 illustrates one example of a wireless network 100 for lighting control. The bi-directional solid lines among a system controller (or a lighting controller) and the plurality of nodes (or lighting units) refer to the multi-hop wireless communication links, such as ZigBee or BLE mesh, over which control/configuration/RDM communication takes place. The received control or configuration information may be provided to a driver of a lighting device for lighting control. The unidirectional dash lines indicate broadcasting of DMX streaming data from the system controller to the plurality of nodes over the frequency hopping based spread spectrum radio link. The lighting controller and the controlled light units may be equipped with communication modules which can bridge DMX and multi-hop communications.

FIG. 3 illustrates a basic block diagram of a node 301 -3 On out of a plurality of nodes 301-30n comprised in a wireless network 100. As a basic example, the node 301-30n comprises a transceiver 311, a first receiver 312, and a controller 313. The transceiver 311 is configured to operate according to a first communication protocol. The first receiver 312 is configured to operate according to a second communication protocol. The controller 313 is configured to: enable the transceiver 311 when the wireless network 100 is in a network control mode; and enable the first receiver 312 when the wireless network 100 is in a data streaming mode. The first communication protocol supports bi-directional communication over multi -hop routing among a system controller 110 and the plurality of nodes 301-30n, and the second communication protocol supports broadcasting from the system controller 110 to one or more nodes 301-30n out of the plurality of nodes 301-30n based on adaptive frequency hopping.

In another setup, the first receiver 312 is comprised in the transceiver 311, and the controller 313 is further configured to switch the transceiver to operate according to the first communication protocol and the second communication protocol depending on whether the wireless network 100 is in the network control mode or in the data streaming mode.

In one example, the first receiver 312 is a polyphase channelizer receiver. The polyphase channelizer receiver enables simultaneous reception and synchronisation of all available hopping channels at once. This means that true adaptive Frequency Hopping Spread Spectrum (FHSS) (or even simultaneous multicarrier frequency hopping and adaptive simultaneous multicarrier frequency hopping) can now be practically implemented without penalties - there is no need to tune an RF local oscillator from one hopping frequency to another which takes time and limits reception to only a single channel at a time unless multiple independent receivers are implemented in the receiver.

This has a further advantage that a diversity scheme can be implemented whereby data for transmission can be sent simultaneously on multiple low noise hopping channels at once for increased robustness. It also means that an intelligent decision can be made on the spot about which channel or channels are quietest (best SNR) at a particular moment in time for data transmission. As all channels are received simultaneously there is no need to waste channels on providing information over the hopping sequence and more channels are available for data transmission. With the receiver operating in parallel on all channels concurrently also means that a Listen Before Talk (LBT) process can take place on all channels simultaneously giving more opportunities to transmit data as time is not needed to tune a local oscillator across the band and make measurements as to channel noise levels, which could take quite some time to scan the entire band. The parallel channel receiver capability should also enable the radio to determine the nature and time-domain properties of interferers more accurately.

Regarding mesh networking, the digital polyphase channelizer enables the mesh network to also hop instead of being static on one channel where it is prone to interference. For example, Zigbee radios are often limited to a choice of only 3 possible channels for use due to the presence of both Wi-Fi devices and the heavy use by BLE of the Primary Advertising Channels, one of which overlaps directly with Zigbee channel 15 and has made this channel too noisy to be used anymore by other radios.

FIG. 4 exemplarily shows a flow chart of a method 800 for operating a wireless network 100. A method 800 for operating a wireless network 100 comprising a system controller 110 and a plurality of nodes 301-30n, the method 800 comprising steps of operating, in step S801, the wireless network 100 in a network control mode according to a first communication protocol; operating, in step S802, the wireless network 100 in a data streaming mode according to a second communication protocol; wherein the first communication protocol supports bi-directional communication over multihop routing among the system controller 110 and the plurality of nodes 301-30n, and the second communication protocol supports broadcasting from the system controller 110 to one or more nodes 301-30n out of the plurality of nodes 301-30n based on frequency hopping.

Optionally, the method 800 further comprises: broadcasting, in step S803, data according to a Digital Multiplex DMX protocol from the system controller 110 to the one or more nodes 301-30n in the data streaming mode.

Optionally, the method 800 further comprises: transmitting, in step S804, a configuration or control signal from the system controller 110 to the plurality of nodes 301-30n in the network control mode.

FIG. 5 exemplarily shows a flow chart of a method 800 for operating a wireless network 100. In this example, the method 800 further comprises an optional initialization phase, such that the method further comprises: initializing, in step S805, the wireless network 100 in the network control mode; switching, in step S806, the wireless network 100 between the data streaming mode and the network control mode according to a time schedule.

The time schedule may be predetermined or preconfigured, such that it is a fixed switching pattern. Alternatively, the time schedule may be configurable or adaptive, such that it may change or evolve according to at least one of a real-time traffic load for data streaming, a latency requirement of data streaming, a latency requirement of the configuration or control signal, a user input, a trigger event, or a combination thereof.

The first communication protocol may be a wireless mesh communication protocol, such as based on Zigbee mesh, BLE mesh, Thread, Z-Wave, or another short range wireless mesh communication protocol.

Preferably, the second communication protocol supports broadcasting based on adaptive frequency hopping, which dynamically changes the frequency channel used for transmission based on the wireless channel conditions.

Even more preferably, the second communication protocol supports broadcasting based on simultaneous multicarrier frequency hopping or adaptive simultaneous multicarrier frequency hopping. Simultaneous Multicarrier Frequency Hopping (SMFH) makes use of multiple carrier frequencies that are hopped between in a simultaneous manner. By spreading the signal over multiple frequency channels, SMFH is more resistant to interference and fading, and may support higher data rate. In SMFH, each carrier frequency is typically hopped independently and randomly, which makes it also very difficult for an eavesdropper to intercept the signal. Adaptive Simultaneous Multicarrier Frequency Hopping (ASMFH) is an advanced version of SMFH, which uses adaptive algorithms to dynamically adjust the hopping patterns based on the current channel conditions. Thus, ASMFH has even better performance in terms of interference robustness and security.

FIG. 6 shows one example of a method for operating a wireless network 100. As an example of the operation sequence of the proposed system, the network is initialized, such as upon powering on, in the secure (Zigbee) mesh communication mode to set network configuration parameters and dual mode or dual-protocol operation parameters. In this example, the first communication protocol is according to Zigbee mesh for illustration purpose. Optionally, RDM requests can be sent from a system controller or lighting controller to one or more lighting nodes to verify the system health. Upon completion of initial system check, a command is set to trigger DMX streaming mode after a predefined time interval, which may be sufficient for the messages to propagate through the mesh network. Thus, the predefined time interval may be determined according to the size of the mesh network. Following this, the lighting controller starts transmitting DMX packets over the AFHSS broadcast link. After the transmission of one or more DMX packets, the system controller may be configured to determine if it is necessary to switch to the mesh network mode or to stay in the AFHSS mode.

Alternatively, it may also be configured that at the end of each DMX packet reception or a certain period of DMA packet reception, the lighting nodes automatically switch to the mesh network mode for the same predefined interval as used in the initialization phase or another predefined interval to execute any further control/config/RDM commands and then switch back to the AFHSS mode for streaming data operation.

The method according to the present invention may be implemented on a computer as a computer implemented method, or in dedicated hardware, or in a combination of both.

Claims

CLAIMS:

1. A method (800) for operating a wireless network (100) comprising a system controller (110) and a plurality of nodes (301 -3 On), the method (800) performed by the system controller (110) comprising steps of: operating (S801) the wireless network (100) in a network control mode according to a first communication protocol; operating (S802) the wireless network (100) in a data streaming mode according to a second communication protocol; initializing (S805) the wireless network (100) in the network control mode; switching (S806) the wireless network (100) between the network control mode and the data streaming mode according to a time schedule; wherein the first communication protocol is a wireless mesh communication protocol that supports bi-directional communication over multi-hop routing among the system controller (110) and the plurality of nodes (301 -3 On), and the second communication protocol supports broadcasting from the system controller (110) to one or more nodes (301 -3 On) out of the plurality of nodes (301 -3 On) based on frequency hopping.

2. The method (800) of claim 1 further comprising: broadcasting (S803) data according to a Digital Multiplex (DMX) protocol from the system controller (110) to the one or more nodes (301 -3 On) in the data streaming mode.

3. The method (800) of claim 1 or 2 further comprising: transmitting (S804) a configuration or control signal from the system controller (110) to the plurality of nodes (301 -3 On) in the network control mode.

4. The method (800) of claim 3, wherein the configuration or control signal is according to a Remote Device Management, RDM, protocol.

5. The method (800) of any one of the previous claims, wherein the time schedule may be predetermined or configurable according to at least one of a real-time traffic load for data streaming, a latency requirement of data streaming, a latency requirement of the configuration or control signal, a user input, a trigger event, or a combination thereof.

6. The method (800) of any one of the previous claims, wherein the second communication protocol supports broadcasting based on adaptive frequency hopping.

7. The method (800) of any one of the previous claims, wherein the second communication protocol supports broadcasting based on simultaneous multicarrier frequency hopping or adaptive simultaneous multicarrier frequency hopping.

8. A node (301 -3 On) out of a plurality of nodes (301 -3 On) comprised in a wireless network (100); wherein the wireless network (100) comprises a system controller (110) and the plurality of nodes (301-30n); wherein the system controller is configured to initialize the wireless network (100) in a network control mode, and switch the wireless network (100) between the network control mode and a data streaming mode according to a time schedule; the node (301-30n) comprising: a transceiver (311) configured to operate according to a first communication protocol; a first receiver (312) configured to operate according to a second communication protocol; and a controller (313) configured to: o enable the transceiver (311) when the wireless network (100) is in a network control mode; and o enable the first receiver (312) when the wireless network (100) is in a data streaming mode; wherein the first communication protocol is a wireless mesh communication protocol that supports bi-directional communication over multi-hop routing among the system controller (110) and the node (301 -3 On), and the second communication protocol supports broadcasting from the system controller (110) to the node (301 -3 On) based on frequency hopping.

9. The node (301-30n) of claim 8, wherein the first receiver (312) is a polyphase channelizer receiver.

10. The node (301-30n) of claim 8 or 9, wherein the first receiver (312) is comprised in the transceiver (311), and the controller (313) is further configured to switch the transceiver to operate according to the first communication protocol and the second communication protocol depending on whether the wireless network (100) is in the network control mode or in the data streaming mode.

11. A wireless network (100) comprising a system controller (110) and a plurality of nodes (301-30n) according to claim 8; wherein the system controller (110) is configured to: operate the wireless network (100) in a network control mode according to a first communication protocol; operate the wireless network (100) in a data streaming mode according to a second communication protocol; initialize the wireless network (100) in the network control mode; switch the wireless network (100) between the network control mode and the data streaming mode according to a time schedule; wherein the first communication protocol is a wireless mesh communication protocol that supports bi-directional communication over multi-hop routing among the system controller (110) and the plurality of nodes (301 -3 On), and the second communication protocol supports broadcasting from the system controller (110) to one or more nodes (301 -3 On) out of the plurality of nodes (301 -3 On) based on frequency hopping.

12. The wireless network (100) of claim 11, wherein the system controller (110) is configured to: transmit a configuration or control signal to one or more nodes (301 -3 On) out of the plurality of nodes (301 -3 On) in the network control mode; and broadcast data to one or more nodes (301 -3 On) out of the plurality of nodes (301 -3 On) based on frequency hopping in the data streaming mode.

13. The wireless network (100) of claim 11 or 12, wherein one or more nodes

(301 -3 On) out of the plurality of nodes (301 -3 On) are integrated in or attached to a luminaire.

14. The wireless network (100) of any one of the previous claims 11-13, wherein the system controller (110) is a controller node according to a Digital Multiplex (DMX) system, a Remote Device Management, RDM, system, or another digital communication protocol for lighting control.

15. The wireless network (100) of any one of the previous claims 11-14, wherein the system controller (110) is further configured to broadcast based on adaptive frequency hopping, simultaneous multicarrier frequency hopping, or adaptive simultaneous multicarrier frequency hopping.